Create ListView Builder from StreamBuilder with ISAR Database - flutter

Question

I am trying to create a ListView Builder from Stream builder in Flutter.
TodoList Class
import 'package:isar/isar.dart';
part 'todo_list.g.dart';
#Collection()
class TodoList {
Id id = Isar.autoIncrement;
late String todoTitle;
}
Isar Services
class IsarService {
late Future<Isar> db;
IsarService() {
db = openDB();
}
//Return IsarDB, if not found, then create
Future<Isar> openDB() async {
if (Isar.instanceNames.isEmpty) {
return await Isar.open(
[TodoListSchema],
inspector: true,
);
}
return Future.value(Isar.getInstance());
}
Stream<List<TodoList>> listenToTodoList() async* {
final isar = await db;
yield* isar.todoLists.where().watch(fireImmediately: true);
}
}
ListView Builder from above Streambuilder
class ListScreen extends StatefulWidget {
final IsarService service;
const ListScreen(this.service, {super.key});
#override
State<ListScreen> createState() => _ListScreenState();
}
class _ListScreenState extends State<ListScreen> {
//Text Controller
final _textController = TextEditingController();
final service = IsarService();
//Let's build List Title from snapshot
final List<TodoList> _todoList = [];
//Root widget of the class
#override
Widget build(BuildContext context) {
return Scaffold(
//List Screen Body Section
body: StreamBuilder(
stream: service.listenToTodoList(),
builder: (context, snapshot) {
if (snapshot.hasError) {
AlertDialog(
content: Text(snapshot.error.toString()),
);
} else if (snapshot.hasData) {
_todoList.add(snapshot.data); //Error happen in this line
}
return const CircularProgressIndicator();
},
),
);
}
}
The Error is
The argument type 'List?' can't be assigned to the parameter type 'TodoList'.
I'am trying to assign the snapshot data in final List<TodoList> _todoList = []; and use them ListView Builder

Answer 1

Try this code:
return Scaffold(
body: StreamBuilder(
stream: service.listenToTodoList(),
builder: (context, snapshot) {
if (snapshot.hasError) {
AlertDialog(
content: Text(snapshot.error.toString()),
);
} else if (snapshot.hasData) {
final todos = snapshot.data;
if (todos != null) {
return ListView.builder(
itemCount: todos.length();
itemBuilder: (context, index) {
final todo = todos[index];
return Text(todo.todoTitle);
}
);
} else {
return const Center(child: Text('No data found!'));
}
}
return const CircularProgressIndicator();
},
),
);